In the hybrid vehicle, for example, in order to improve fuel consumption efficiency, it is known to enable the internal combustion engine to perform lean combustion (e.g. refer to Patent Literatures 1 and 2).
Moreover, in order to prevent a torque shock, deterioration of durability of a friction material, and the like in speed change or gear shift, it is known to perform torque down control on the internal combustion engine in the speed change (refer to Patent Literatures 3 and 4).